1. Field of the Invention
The present invention relates to a tray for positioning an open cell liquid crystal display (LCD) panel, more particularly to a tray having limiting structures.
2. Description of the Related Art
Nowadays, LCD panels are packaged in different ways. Some of them are mainly packaged with plastic discs, some of them are mainly packaged with injection boxes, and some of them are mainly packaged with foam products. LCD panels exist in two forms, which are cell type and open-cell type as defined by the industry. A cell LCD panel is a liquid crystal box formed by disposing liquid crystal molecules between two glass substrates, and its appearance is not different from the ordinary sheet glass. An open cell LCD panel is formed by disposing various ports on the cell LCD panel so that external signal sources are allowed to be connected. However, the open cell LCD panel does not comprise components such as backlight, bezel, etc. which always exist in the liquid crystal module (LCM).
Usually, more than one PC boards (PCBs) of the open cell LCD panel are connected by a flexible sheet. Such a flexible sheet, called as a chip-on-film (COF), is distributed with circuit to bridge signals between the open cell LCD panel and the PCBs. The open cell LCD panel is usually placed in a tray and kept flat, and the positioning devices of the tray are used for positioning the periphery of the open cell LCD panel. When the open cell LCD panel is subject to vibration, the PCBs tend to displace and pull the COF to cause damage to it. Hence, the product quality is impacted. Furthermore, since the COF is a flexible sheet, the PCBs tend to be carried into the gap between two liquid crystal boxes owing to the vibration. In the current packaging method for the open cell LCD panels, columns are directly formed when the plastic disc tray is formed. As shown in FIG. 1 and FIG. 2, an open cell LCD panel A 1 only has one COF 2, and two columns 5 of the tray 4 are used for stopping a PCB 3. Such a method is only suitable for a single tray for accommodating a very few open cell LCD panels. Once the number of the open cell LCD panels is large, the column 5 becomes taller. Due to the blockage of the columns 5, the PCB 3 tends to be hung on the columns 5 when placing and displacing the open cell LCD panel. As a result, the COF 2 is pulled and damaged to impact product quality. The capacity for the current used tray is four, and the columns 5 are simultaneously formed when the tray 4 is produced. Consequently, the universality of the tray 4 is questionable. In addition, please also refer to FIG. 3, if the tray 4 is intended to be used for accommodating an open cell LCD panel B 6 that has a plurality of COFs connecting with a PCB 8, the two centered COFs 7 will collide with the two columns 5 of the tray 4. The tray 4 is therefore not able to accommodate the open cell LCD panel B 6. For a tray being able to do so, a new mold needs to be made to fabricate trays for the open cell LCD panels B 6. As a result, the cost of the mold is a waste. Moreover, since the trays are used repeatedly, the package resource is also wasted to increase production cost if they are not applied universally.